1. Field of the Invention
The present invention relates to improvement on the structure of a measuring tape device, in particular, it refers to a measuring tape device with which the precision of measurement will not be skewed by thickness of the hook member located at the distal end of a measuring tape and/or the gap caused by the movable mechanics of the hook member.
2. Description of Prior Art
It is a known fact that measuring tape device is a rather mechanical and convenient device amongst various types of measuring tools. As shown in FIG. 1A, a conventional measuring tape device 1 contains a coilable tape 12 that is spring-loaded (not shown in the drawings) within a casing 11. The measuring tape device 12 has a hook member 13 secured to the distal end of a measuring tape. The hook member 13 is composed of two parts: (1) the backing plate 14 that is secured to the distal end of the tape by rivets and (2) the perpendicularly-extended part 15 is the leg piece of the hook member. During application, the hook member 13 can be used to hang onto or grasp to an object of measurement so to allow the tape to measure the distance/length between an object of measurement and a designated point.
However, for a conventional measuring tape device, the hook member 13 can only be applied to either hook onto or push against an object of measurement; in the case that the measurement is to be applied on a flat/smooth surface, it often happens that there is no anchor point for the hook member, so that the measuring process can only be carried out with the surface of the measuring tape loosely glides along the top of and/or pushes against the surface of the object of measurement. Since there is no fastened grip at the distal end of the measuring tape for a proper measurement, the process and the outcome of the measurement is therefore inevitably affected.
In order to resolve the issue of hook member anchoring, manufacturers tried to come up with ideas that placed magnetic piece at the leg piece of the hook member. As shown in FIG. 1B per Taiwan Patent Publication No. 405703, in which it disclosed a hook member that contained a mount opening at the leg piece of the hook member, a magnetic piece of same dimension as the opening was then mounted into the opening, and was formed as part of the body of the leg piece of the hook member. In an alternative invention as shown in FIG. 1C per Taiwan Patent Publication No. M258275, the invention used a plug-in mechanism that allowed a magnetic piece to be plugged into a pre-set slot at the leg piece of the hook member and the magnetic piece was formed as part of the body of the leg piece of the hook member, so that it achieved similar effect as that of the invention per shown in FIG. 1B. Another example as shown in FIG. 1D per U.S. Pat. No. 6,874,245, in which it disclosed an L-shape magnetic riveting piece that was connected to the distal end of a measuring tape, the front portion of the magnetic riveting piece is protected with a cover, so that it in effect became the leg piece of the hook member, which was then to be used to either hook onto or magnetically attached to the object of measurement. A further example as shown in FIG. 1E per U.S. Pat. No. 7,240,439, in which the invention contained a hook member on which there was mount opening, a magnetic piece was mounted into the mount opening so that it was formed as part of the body of the leg piece of the hook member and then the hook member was protected with a cover. As a result, the hook member could either be hooked onto or magnetically attached with the object of measurement.
Based on the above patented inventions, it was obvious that the inventors' intentions were to improve anchoring stability during measuring process. By attaching a magnetic piece to the leg piece of a hook member of a measuring tape device, the inventions utilized the attractive nature between a hook member that was magnetized and an object of measurement that was metallic. As such, the anchoring stability between a measuring tape and a metallic object of measurement could be improved. However, as shown in FIG. 1F, although magnetic piece 14 was placed onto the hook member of most of the above patented inventions, the magnetic piece 14 was thicker than the leg piece of the hook member; as such, in order to align the anchored starting point on the surface of the object of measurement with the magnetic piece that was on the hook member, the hook member must be designed so that it allowed the hook member to be movable forward or backward when necessary. Yet during measuring process, when a hook member was to be pushed against or magnetically attached to the metallic surface of the object of measurement, these designs still resulted in measurement imprecision caused by thickness of the hook member and/or the gap d that was effected from the movable mechanics of the hook member. Besides, the magnetic piece mentioned in most of the above inventions was mounted onto a mount opening of a hook member of the measuring tape, as such, in the case that the measuring tape device was to be dropped or if the hook member was to be impacted with another hard object, then there would be a great chance that the magnetic piece to be fell off the hook member, and thus caused operational nuisance.